骨密度降低的病因诊断——陷阱与对策

骨密度降低分为代谢性骨密度降低和破坏性骨密度降低,前者为全身性改变,后者常为局部性表现.引起骨密度降低的原因众多,本文列举了骨密度降低的各种情况,分析了其可能的病因.并指出目前的骨密度测定方法仍存在局限性,提出了原发性骨质疏松诊断和鉴别诊断的具体方法.     

Potassium and phosphorus repletion in hospitalized patients: implications for clinical practice and the potential use of healthcare information technology to improve prescribing and patient safety

ABSTRACT

Objectives: Evaluate potassium and phosphorus repletion in hospitalized patients. Assess the potential role for use of various methods, including healthcare information technology, to improve prescribing and patient safety.

Research design and methods: Inpatient medication profiles were screened to identify orders for potassium and phosphorus replacement products. Electronic laboratory and medical records were used to evaluate efficacy and safety. Eligibility for oral therapy was defined by the presence of other scheduled oral medications on the medication profile. Appropriateness of prescribing was based on adherence to the hospital guidelines for repletion.

Results: Overall, 134 orders for potassium in 92 patients and 36 orders for phosphorus in 27 patients were evaluated over a 3-week data collection period. Intravenous (IV) potassium was prescribed in 73% of replacement episodes (46% as single doses and 54% within large volume IV fluids), with 85% for normokalemia or mild-to-moderate cases of hypokalemia. Phosphorus orders involved single doses of IV potassium phosphate (mean 13.1 mmol) in 75% of cases. Approximately 85% of doses were for mild or moderate hypophosphatemia. Eligibility for oral therapy was evident in 74% of normokalemic or mild hypokalemic cases receiving IV potassium products and in 33% of cases receiving IV phosphorus replacement. Six cases of mild hyperkalemia were observed. No hyperphosphatemia was documented.

Study limitations include use of a retrospective design, inability to discern whether some electrolyte doses were given with a preventative intent, potential overestimation of the number of patients eligible for oral repletion, and lack of data on the accessibility of the laboratory serum concentrations or the awareness of serum values to the prescribers.

Conclusions: Intravenous potassium and phosphate products are commonly prescribed for mild or moderate cases of hypokalemia or hypophosphatemia. Many patients met eligibility for oral therapy. Efforts to enhance prescriber education and implement computerized prescribing and decision support systems have the potential to improve prescribing and reduce possibilities of adverse drug events and medication errors related to potassium and phosphate administration.     

A case of familial tumoral calcinosis/hyperostosis–hyperphosphatemia syndrome due to a compound heterozygous mutation in GALNT3 demonstrating new phenotypic features

Summary  A new case of familial tumoral calcinosis (FTC)/hyperostosis–hyperphosphatemia syndrome (HHS) due to a novel compound heterozygous mutation in N-acetylgalactosaminyltransferase 3 (GALNT3) and with new phenotypic findings is presented. The response in serum phosphate and fibroblast growth factor 23 (FGF23) to medical treatment is detailed. This case expands the genotype and phenotype of FTC/HHS and gives insight into its treatment and pathophysiology. Introduction  FTC and HHS are caused by mutations in FGF23, GALNT3, or KLOTHO. They are characterized by hyperphosphatemia, increased phosphate reabsorption, and elevated or inappropriately normal serum 1,25-dihydroxyvitamin D₃ (1,25-D₃); FTC is associated with calcific masses, and HHS with diaphyseal hyperostosis. Methods  A 36-year-old woman presented with abnormal dental X-rays at age 12 and was hyperphosphatemic at 22. She underwent radiographic, biochemical and genetic testing, and medical treatment. Results  Serum phosphorus was 7.3 mg/dL (2.5–4.8), TmP/GFR 6.99 mg/100 mL (2.97–4.45), 1,25-D₃ 35 pg/mL (22–67). Radiographs revealed tooth anomalies, thyroid cartilage calcification, calcific masses in vertebral spaces, calcification of the interstitial septa of the soft tissue in the lower extremities, and cortical thickening of the long bones. Her total hip Z score was 1.9. C-terminus serum FGF23 was 1,210 RU/mL (20–108), but intact FGF23 was 7.4 pg/mL (10–50). DNA sequencing determined she was a compound heterozygote for mutations in GALNT3. Treatment with niacinamide and acetazolamide decreased TmP/GFR and serum phosphate, which was paralleled by a decrease in serum C-terminus FGF23. Conclusions  This case broadens the spectrum of phenotypic and genotypic features of FTC/HHS and suggests treatments to decrease renal phosphate reabsorption in the setting of a low intact FGF23.     

蔗糖蜜生产酵母中磷的吸光光度测定法

目的探讨蔗糖蜜生产酵母中磷测定的样品制备与吸光光度分析方法。方法利用三氯乙酸、TritonX-100、柠檬酸混合溶液对样品的磷含量进行有效消解、浸提,并用吸光光度法进行测定。结果该方法测定结果满意,平均回收率（n=5）达96.4％-101.6％,变异系数为1.4％-1.6％。结论该样品处理及测定方法简单方便、经济实用。     

对血液透析患者钙磷代谢异常改进治疗的研究

目的改进对血液透析患者钙磷代谢异常的治疗,观察患者生活质量的改善。方法按照美国肾脏基金会（NKF）制定的“慢性肾脏病,透析病人生存质量指南（K/DOQI）”改进对血液透析患者钙磷代谢异常的治疗,观察1年后患者的血清钙、磷、钙磷乘积、全段甲状旁腺素（iPTH）等水平及治疗达标率的变化。应用肾脏病调查表（KDQ）评估患者生活质量的改善。结果改进治疗后患者的血清钙、磷、钙磷乘积及iPTH水平均较改进治疗前有明显下降（P〈0．01或〈0．05）。改进治疗后治疗达标率分别为：血清钙74．42％（32／43）、血清磷62．79％（27／43）、钙磷乘积55．81％（24／43）、iPTH60．47％（26／43）、四项达标25．58％（11／43）,均较改进治疗前有明显上升（P〈0．01或〈0．05）。改进治疗后KDQ评分的总分及各方面得分均较改进治疗前有明显增中（P〈0．01）。结论改进治疗后患者钙磷代谢隋况较改进治疗前改善,生活质量提高。     

对血液透析患者钙磷代谢异常改进治疗的研究

目的 改进对血液透析患者钙磷代谢异常的治疗,观察患者生活质量的改善.方法按照美国肾脏基金会(NKF)制定的"慢性肾脏病,透析病人生存质量指南(K/DOQI)"改进对血液透析患者钙磷代谢异常的治疗,观察1年后患者的血清钙、磷、钙磷乘积、全段甲状旁腺素(iPTH)等水平及治疗达标率的变化.应用肾脏病调查表(KDQ)评估患者生活质量的改善.结果改进治疗后患者的血清钙、磷、钙磷乘积及iPTH水平均较改进治疗前有明显下降(P<0.01或<0.05).改进治疗后治疗达标率分别为:血清钙74.42%(32/43)、血清磷62.79%(27/43)、钙磷乘积55.81%(24/43)、iPTH 60.47%(26/43)、四项达标25.58%(11/43),均较改进治疗前有明显上升(P<0.01或<0.05).改进治疗后KDQ评分的总分及各方面得分均较改进治疗前有明显增加(P<0.01).结论改进治疗后患者钙磷代谢情况较改进治疗前改善,生活质量提高.     

Ingestion of potato starch containing high levels of esterified phosphorus reduces calcium and magnesium absorption and their femoral retention in rats

Many studies have shown that esterified phosphorus (P) in diets has a favorable effect on mineral absorption in humans and animals. Phosphorylated oligosaccharides derived from potato starch increase calcium (Ca) absorption from the rat intestine both in situ and in vitro. We hypothesized that the feeding of potato starch has a potential to increase Ca or magnesium (Mg) absorption. Male Sprague-Dawley rats at 7 weeks were fed 4 types of diet containing either 60% sucrose, cornstarch, or 1 of 2 types of potato starch with different P contents for 1, 3, or 5 weeks. A balance test for Ca, Mg, and P was undertaken, and these mineral contents in the femur were determined for the 4 diet groups at each feeding period in vivo. Ingestion of potato starch increased Ca, Mg, and P excretion into feces and decreased the absorption rate of Ca and Mg. Femoral Ca contents were also decreased in the rats fed the potato starch diets compared with those in rats fed the sucrose or cornstarch diet. In vitro experiment in Ca absorption was undertaken using everted jejunal and ileal sacs of the small intestine in male Sprague-Dawley rats (7 weeks old). The potato starch application did not induce significant increase in Ca absorption compared with nonstarch (control) or cornstarch application. In conclusion, the ingestion of potato starch does not increase Ca and Mg absorption and rather accelerates their excretion, inducing the decrease in mineral absorption and retention in growing rats.     

急性白血病肝浸润~(31)P磁共振波谱学分析及临床意义

目的:通过对白血病肝脏浸润(LIL)病例与正常对照组的肝脏二维化学位移磁共振31磷波谱成像(2D CSI ~(31)P MRS)对照研究,探讨LIL的肝脏磷化合物代谢特征变化.方法:收集LIL 15例,并与12例正常肝脏作对照,进行2D CSI ~(31)P MRS肝脏扫描,检测各种磷代谢物包括磷酸单酯(PME)、磷酸双酯(PDE)、三磷酸腺苷(ATP)、无机磷(Pi)的相对值,经体模所测校正系数校正后,分析PME、PDE、Pi、ATP的校正相对值(以下简称相对值),及PME/PDE、PME/ATP、PDE/ATP、Pi/ATP、 PME/(PME+PDE)的比值变化.结果:在所测的肝脏磷代谢物相对值中,仅LIL组的PME相对值升高,为1.992±0.876,与对照组(1.167±0.427)相比有显著性差异,P<0.05;其它各磷代谢物相对值均无差异.比较LIL与正常对照组之间磷代谢物比值,发现LIL组中与PME相关的比值包括PME/PDE、PME/ATP和PME/(PME+PDE)比值升高,分别为0.551±0.339、1.402±0.654和0.326±0.13,与对照组(分别为0.254±0.059、0.792±0.232和0.199±0.049)相比有显著性差异,P<0.01;LIL组的其它磷代谢物比值与对照组相比均无显著差异.结论:肝~(31)P MRS检查为LIL提供新的非创伤性检测和评价方法,肝脏PME相对值及其相应比值升高提示白血病患者肝浸润存在的可能.     

添加化学试剂控制湖泊底泥内源磷释放的实验研究

目的 研究添加化学试剂对湖泊底泥内源磷释放的抑制效果,为城市内湖综合治理措施的制定提供技术依据.方法 于2008年5月20日,采集莫愁湖上层底泥样品和水样.对底泥进行磷形态[总磷(TP)、NaOH-P、HCl-P、无机磷(IP)、有机磷(OP)]的分析,测定水样的pH值和TP的含量.分别向水(250ml)-底泥(10g)系统中投加0～1 000.0mg/L的Ca(OH)_2、0～10.0 mg/L的Al_2(SO_4)_3和0-25.0mg/L的FeCl_3,测定水样pH值和TP的含量,并计算TP的释放控制率.结果 莫愁湖水样的pH值在7.6～8.0之间,TP含量为2.0 mg/L.底泥中的TP、HCl-P、NaOH-P、IP、OP的含量分别为2 187.06、1 383.89、526、48、1910.37、276.69mg/kg.随着Ca(OH)_2:浓度的增加,水体pH值迅速上升,TP含量呈下降趋势,TP的释放控制率呈升高趋势.随着Al_2(SO_4)_3 或FeCl_3浓度的增加,水体pH值略有下降,TP含量呈下降趋势,TP的释放控制率呈升高趋势.结论 Ca(OH)_2、Al_2(SO_4)_3、FeCl_3对湖泊底泥内源磷的释放具有明显的抑制作用.     

Hypoparathyroidism: what is the best calcium carbonate supplementation intake form?

Introduction

In hypoparathyroidism, calcium supplementation using calcium carbonate is necessary for the hypocalcemia control. The best calcium carbonate intake form is unknown, be it associated with feeding, juice or in fasting.